The importance of early interaction for normal development is widely acknowledged but not well understood. Two analyses are proposed to investigate how mother-child conversation influences child language development. The data base for these analyses consists of existing longitudinal records of conversations between 22 mothers and their two-year-old children. An analysis of mothers' communicative intentions investigates the relations among mothers' purposes in talking to their children, structural properties of mothers' speech to their children, and the rate of those children's syntax growth. Previous research has established that mothers' communicative intentions motivate modifications in their speech to children and that properties of maternal speech influence child language growth. This study is unique in assessing the interrelationships among maternal intentions, maternal speech, and child language growth in a single sample. Relating the benefit of mothers' speech to their communicative intentions potentially provides a basis for intervening to improve the quality of mother-child interaction. An analysis of child responses to mothers' speech is designed to look for differences in the form of child responses to categories of mothers' speech with different relations to child language growth. Those child responses can be used as clues to the nature of the processing the child applies to the speech he hears and thus contribute to explicating the mechanism by which mother-child conversation influences child language development. A description of child behaviors associated with language-advancing conversation could also be used to identify beneficial interaction in future research and in applied settings where assessment of ongoing interaction is desired. The objective of this research is to provide an understanding of what takes place in mother-child conversation and how that interaction influences child language development. That understanding should provide the basis for identifying and imporving non-optimal interaction.